Agitators intended for the preparation of mixtures, solutions, emulsions etc. are known to the art, for instance from Austrian Patent Specification 265 991. These known apparatus are used, for instance, to prepare beverages, purify water or for various kinds of biological processes. The apparatus may comprise an egg-shaped reaction vessel which accommodates the liquid to be processed. Arranged in the lower parts of the vessel is a single-blade or multi-blade device which is driven from beneath the vessel, while arranged in the upper part of the vessel is an inlet opening for the introduction of secondary solid, liquid or gaseous additive substances into the vessel.
One problem with such apparatus and other, similar apparatus is that they generate turbulent flows which move in mutually different directions and therewith counteract the generation of a desired natural vortex, a problem which can only barely be solved and then at the price of a higher energy input. No optimal solution has hitherto been proposed, however.
The object of the present invention is, inter alia, to eliminate the aforesaid drawbacks in a rational, energy-lean and therewith environmentally friendly manner, by isolating any possible turbulent liquid movement from a vortex which is engendered naturally in regions above the rotatable device, provided that no disturbances are conducted upwardly towards the centre of the vortex. This will also result in all of the liquid mass accompanying the rotational movement. By vortex is meant here all manner of ordered movement of fluid particles which will generate a central vacuum and therewith a downward suction force.